Electrical circuit protector having auxiliary indicating switch contacts



4 Sheets-Sheet 1 A. W. KRIEGER ELECTRICAL CIRCUIT PROTECTOR HAVINGAUXILIARY INDICATING SWITCH CONTACTS Oct. 26, 1965 Filed May 13, 1963 ww 3% @m Oct. 26, 1965 A. w. KRIEGER 3 214,537

, ELECTRICAL CIRCUIT PROTECTOR HAVING AUXILIARY INDICATING SWITCHCONTACTS Filed May 13, 1963 4 Sheets-Sheet 2 Oct. 26, 1965 A. w. KRIEGERELECTRICAL CIRCUIT PROTECTOR HAVING AUXILIAR INDICATING SWITCH CONTACTS4 Sheets-Sheet 3 Filed May 15, 1963 Oct. 26, 1965 A. w. KRIEQGER 3214,537

ELECTRICAL CIRCUIT PROTECTOR HAVING AUXILIARY INDIGATING SWITCH CONTACTSFiled May 13, 1965 4 Sheets-Sheet 4 .IIII].

United States Patent i 3,214,537 ELECTRICAL CIRCUIT PROTECTOR HAV- INGAUXILIARY INDICATING SWITCH CONTACTS I Alvin W. Krieger, 315 N. 12thSt., P.O. Box 463,

, Milwaukee, Wis.

Filed May 13, 1963, Ser. No. 285,176 12 Claims. (Cl. 200- 106) This is acontinuation-impart of my application Serial No. 258,348 filed February13, 1963, now abandoned.

This invention relates to electrical-circuit protectors. While notlimited thereto the circuit'p'rotector of the present invention isparticularly suited for protecting circuits in electronic dataprocessing apparatus and the in placeof fuses, and are designed, whenconnected in a suitable manner, to provide direct and remote indicationsof their tripping as well as interruption of their immediate circuit,and another, such as a main'power supply circuit or the like.

It is a primary object of the present invention to provide improvedformsof circuit protectors of the aforementioned type.

Another object is to provide circuit protectors of'the aforementionedtype in both thermal and magnetic trip versions. I I s A further objectis to provide a simplified tripping and reset mechanism for such circuitprotectors which comprise relatively few and easily manufactured parts.

A still further object is to 'prov'ide tripping and reset mechanismswhich are characterized by requiring only small electrical faultinitiated forces to effect tripping while affording normalcurrentpositions under the action FIG. 2 and is substantially a right-hand endview of FIG. 3;

FIG. 5 is an elevational view with'portions broken away to show thedevice in another of its operating conditions; V

FIG. 6 is a fragmentary sectional-view similar to FIG.

4 but in still another operating condition;

FIG. 7 is an isometric view ofcertain parts of the device in theirassembled relationship;

FIG. 8 is a front elevational view of a modified form of the device;

FIG. 9 is a partial sectional view taken along line 9-9 FIG. 10 is afragmentary view similar to FIG. 8 showing another modified form ofthedevice;

FIG. 11 is a fragmentarysectional view taken generally along line 1111in FIG. 10; and

FIG. 12 is an isometric view of the parts which comprise themodification shown in FIGS. 10-12.

3,214,537 Patented Oct. 26, 1965 ice As seen in FIGS. 1-6, the circuitprotector has a'molded insulating base 2 to which a mounting plate 4 anda cover plate 6 are mounted by means of a pair of screws 8. Mountingplate 4 has a pair of tapped holes 411 for mounting the protector to apanel or the like, such panel having an opening for the cover plate 6 toextend through, thus exposing the top of cover plate 6, and anyindiciawhich may be on it, to view.

A large cavity'2a is formed in the lower'part of base 2 which is opentothe bottom and one-of its four sides, such side being called thefront. A front cover plate '10 preferably formed of a moldedarc-resistant material,

hastongued edges at its top and'bottom which cooperate with groovesmolded into base 2 and'an'au'xiliary contact base 12-to hold it inplace, thus closingoffthe frontof the cavity2a. Auxiliary'contact base12 is alsoforme'd of a molded insulating materialand held in place byscrews 14'and servesto close the bottom end of cavity 2a.

A support bracket 16 extends through an opening in the sidewall of thebase2, and is riveted to the upper surface ofcavity 2a. One of a pairof-main stationary contacts 18 is secured to a terminal plate 17 which,together with a metal connector strap 17a is riveted tothe upper surfaceof cavity 2a. The other stationary contact member '18 is secured to asecond terminal plate 20, which is also riveted to the upper surface ofcavity 2a and'extends through the other sidewall of base 2. A thirdterminal plate 22 is secured-to the side of base 2 by a hollow rivet(not shown) through which a coil lead will later extend and be solderedto the terminal plate. One of the screws 14 also holds terminal plate 22in place. A hollow cylindrical insulator 24 is held in place betweensupport bracket 16 and terminal plate 22 by apair of screws to giveadditional support to plate 22. I s

A frame member 26a of 'amagnetic coil assembly 26 is also riveted atspaced apart tabs 26b tothe top surface of cavity 2a, and extends downalong the back surface of the cavity. Near the bottom of the cavity,frame member 26a has a horizontal leg portion 260 which extends towardthe front of the device. A coil 26d and a core 26c are held to frame 26wby a screw 26 which takes into' a threaded hole in the frame. One leadof the coil 26d is soldered to connector strap 17a and the other lead isbrought through the hollow rivet which holds terminal 22 in place andthen soldered to the rivet, completing a connection to the terminal 22.

Coil assembly 26 has an armature 26g pivotally mounted at its lower endon leg portion 26c and is biased away from the core 26c by a spring28'which hooks at one end to armature 26g and at its other end threadsover a screw 30 which is free to turn in a retaining member 32 entrappedin auxiliary contact base 12. Proper spring tension upon the armature26g is obtained by turning screw 30 to thread the spring 28 in onedirection or the other upon the screw. Access to the screw 30 isobtained through a hole in auxiliary contact base 12. Once the propertension is obtained, the hole is filled with a sealant, such as-epoxyresin. At its upper end, armature 26g has a screw 34 threaded into atapped hole, this screw serving as'an actuator in a manner to bedescribed later. Screw 34 has a screw driver slot cut into its threadedend to prodownward travel of the contact assembly 36.

molded in base 2 by way of the cavity 2a. sion spring 50 is placedwithin a slot formed in push bar ,end ofthe slot. .the slide tracksalong side of push bar 48.

portion 48a of pushbar 48, and the pin 54a.

.ber 54 forv that.member. helical compression spring 44, trapping pin54a between recess in the upper surface of cavity 2a until plate 38 isheld firmly against a pair of ledges formed in cavity 2a.

Spring 42 rests at its upper end against the top of an enlarged recessin base 2 formed concentric with the recess for screw 40, and at itsbottom end against the upper surface of the movable contact assembly 36.This biases -movable contact assembly 36 down .and away from mainstationary contacts 1818. At its right end as viewed in -FIG. 4, movablecontact assembly 36 has a downwardly bent bearing surface 36 to pivotfrom that point. As can be seen in FIG. 6, plate 38 also serves as alimit to A slot 36b is formed in the center of contact assembly 36 and alatch plate 36c of somewhat harder material is spotwelded to the bottomof contact assembly 36 so that one edge of the latch plate extendsslightly beyond the end of the slot 36b.

A reset latching assembly is mounted in base 2 below cover plate 6. Ahelical compression spring 44 is placed in the main opening andpositioned'around a circular boss.

A second helical compression spring 46 is placed in a cir- A push bar 48is inserted into slide tracks A comprescular recess.

48 and seated at its bottom end against an outwardly and upwardly benttongue portion 48a formed at the lower A spring retaining strap 52 isplaced in An inverted L-shaped latching member 54, having a pin 54ainserted into a hole at the vertex between its arms, is positioned inthe base. A cammed latching surface formed at the-lower end of one legof member 54 is placed through an opening in the base 2 which extendsinto wcavity 2a. A pin 54a is placed througha hole in -springretainingstrap 52 and the upper end of the slot .in push bar 48, trapping spring50 under the pin 54a. Spring 50 is thus held in place by one side wallof. the

slide tracksin base 2, the spring retaining strap 52, tongue Pin. 54a isslightly less in length than the distance between the side- A resetbutton 56 is placed over the member 54. But

.ton 56 has at its lower end a circular boss having spaced transverseslots formed therein to accommodate intermediate portions. of the pin54a, and has acentral clearance slot conforming to the shape of thevertex of mem- The circular boss fits inside of the spring 44 and thetop of its slots.

A trip lever 58 having ahorizontally disposed leg 58a is placed into arecess in base 2 in such a manner as to have leg 58a rest on thehorizontal leg 540 of member :54 at right angles, A helical compressionspring 60,

having its bottom edge 60a extending tangentially, is

placed over an upper cylindrical portion 56a of button 56 so thatportion 60a overlies leg 58a of trip lever 58. Spring 60 also rests onthe upper surface of an enlarged rectangular portion 56b of button 56.

With these items in place, mounting plate 4 is placed on the top of base2 and cover 6 placed over the entire 'assembly in a position to allowstrip lever 58 and button 56 to extend through their respectiveclearance openings in cover 6. The cover is pressed down on the mountingplate 4 against the bias of springs 44, 46 and- 60, and held in place byscrews 8. This causes the mechanism to take the tripped position asindicated in FIG. 6, the cam surface 54b of latching member 54 nowextending through the slot 36b in movable contact assembly 36.

Screw 34 is adjusted by pushing the armature 26g against the face of thecore 26c, and turning screw 34 until it just trips the mechanism. Thenthe screw 34 is given a safety factor by turning it an additional amount(on the order of one quarter turn) and is locked in place by applying asealing compound to the threads where they join the armature.

As can most clearly be seen in FIGS. 5 and 7, the auxiliary contactassembly has three substantially U-shaped terminal members seated incorresponding grooves molded in auxiliary contact base 12. Each of theseterminals has its own base portion 62 with holes therein for theconnection of wires thereto. Extending upwardly along one side of base12 are stamped terminal members 64, 66 and 68 which are riveted to thebases 62. Terminal 64 has riveted to the underside of its upperhorizontal leg a movable contact assembly 70 which is of 'an overcenterspring arrangement and has at its other end a contact member secured onboth its top and bottom surfaces. Terminal 66 has its upper horizontalleg bent at a right angle to its initial direction (FIG. 7) and carrieson the upper surface of that leg a contact member 66a. Terminal 68 has alonger vertical leg than do terminals 64 and 66 and carries a contactmember 68a on the underside of its horizontal leg. An actuator cap 48bmolded of insulating material is secured to the bottom of the olfset armof push bar 48 and bears against a center leg of the movable contactassembly 70 as shown in FIG. 7, causing the movable contacts to trip toone auxiliary position or the other.

In the operation of the circuit protector, let it be assumed that it isinserted in the line to a device it is desired to protect. One wire ofthe device is connected to terminal 22, the other wire connected toterminal 20. The reset button is then pushed down by an operator asshown in FIG. 5. The button bears down on pin 54a and it in turn movesthe vertex of member 54 downward against the bias of spring 44. Pin 54aalso moves push bar 48 down causing cap 48b to press down on the centerleg of movable contact assembly 70, which in turn snaps the movablecontact member into engagement with the upper stationary contact member68a. Auxiliary contact 68a may be connected through relays to a main,

,The amount of travel required to trip the auxiliary con tact assemblyis very small in comparison to the total .travel of button 56, and thetripping occurs at the extreme top end of travel of button 56. Spring 50and the vertical slot in push bar 48 take up the remaining travel of pin54a through button 56 (FIG. 5).

-As button 56 moves farther down, along with latching member 54 and pin5401, the cammed latching surface 54b moves below the latch plate 360.The horizontal leg 54c in following the member 54 compresses spring 46somewhat, causing spring 46 to exert a clockwise moment (as viewed inFIG. 4) upon the member 54, which will move cammed latching surface intoWhen the button 56 is released, the protector will take the position asshown in FIGS. 3 and 4. The spring 44 biases pin 54a and member 54upward, surface 54b then pulling the movable contact assembly 36 intoengagement with main stationary contacts 18-18, this being the limitingfactor in upward travel for the latching member 54, pin 54a, button 56and trip lever 58. A color dividing line 56c on an upper cylindricalportion 56a of the button .will

.lie on the same plane as the top surface of cover plate 6 in thisposition. The portion above the line 560 is the same color as the cover6, and the remainder of the button is of a contrasting color to enable atripped protector to be located more readily. In this position there isnow a circuit completed in the protector from terminal 22 through coil26c, connector strap 17a, terminal 17, contact 18, movable contactassembly 36, the second an overload of current to the device.

contact member 66a.

I device.

contact 18, and terminal 20. Under ordinary conditions this current willhave no effect on the coil, and the particular component it isprotecting will be connected to its main source of power.

Now let us assume that a fault occurs which creates This overload, whenflowing through the coil, will cause the coil to be picked up,attracting armature 26g. Upon movement of armature 26g toward the core26e, screw 34 will strike the cammed surface 54b of member 54, pivotingit counterclockwise about pin 54a and release the movable contactassembly 36, interrupting the circuit to the protected device. Movablecontact assembly 36, with the aid of spring 42 will drop to the positionshown in FIG. 6. The remaining elements will also take the positionshown in FIG. 6, with the contrasting color below the line 56c on button56 now being above the surface of the cover 6 and visible to theoutside. .Push bar 48 has been pulled up by pin 54a and the actuator cap48b has released thecenter leg of movable contact member 70, which hassnapped back into normal contact with lower auxiliary This wouldcomplete a circuit to a warning device, indicating the fault in thatparticular section. Other protectors in the same area may have the likecontact connected in parallel to the same warning The protector willremain in this position as long as the overload in current exists,holding the armature 26g against the core 26e, and screw 34 in place. Ascan be seen in FIG. 6, while it is possible to move button 56 down tocause the auxiliary contacts to trip, the screw 34 will not permit thecammed surface 54b to engage the latch plate 36c and reclose the maincontacts. As mentioned before, should an arc gap occur between "theterminals 16 and 22, it will be isolated within hollow insulator 24.

While little force is required to trip and reset the device, thelatching surface is under relatively heavy pressure (on the order of 1602.). The force required to be exerted to trip the mechanism is verysmall (on the order of 2 02.). Trip lever 58 allows the protector to betripped manually if desired. By pushing down on the exposed'portion oflever 58, a downward force is transmitted to the portion 58a, whichexerts a counterclockwise moment upon leg 540 of member 54 about pin54a.

FIGS. 8 and 9 show another version of the device. The resettingmechanism is the same as the aforedescribed device and for that reasonhas not been shown in detail, and like numbers have been given toidentical parts.

The fundamental differences between the type of circuit protector shownpreviously and the type shown in FIGS. 8 and 9 is that the latter is ofthe thermal trip type, whereas the first described protector was of themagnetic trip type.

The base 72 of the protector shown in FIGS. 8 and 9 is quite similar tothe base 2, except base 72 has provisions for only two terminals and hasa hole 72b in the back wall of cavity 72a for calibrating the device. Alefthand terminal 74 is riveted, together with a frame member 76, tobase 72. A somewhat longer connector strap 75a and a terminal plate 75are also riveted 'to the upper surface of cavity 72a. Connector strap75a extends down along one side wall and then is bent outwardly to nearcenter of the cavity 721;. Frame member 76 is riveted on its right sideto the upper surface of cavity 72a in the same manner as frame 26, andextends down along the rear wall. A horizontal portion 76a extends tothe front and is bent vertically at 76b, which is near the outwardlybent portion of strap 75a. A second vertically bent portion 760containing a guide hole is bent upwardly from horizontal leg 76a betweenthe back wall and portion 76b. In line with the hole 72b in the base 72is a threaded hole 76d on frame 76. A calibrating screw 78 is threadedinto opening 76d and serves as a guide for an actuator of insulatingmaterial and a compression spring 82, and bears against portion 76c,forcing it out from the back wall of the frame. A number of bimetalelements 84 are riveted to strap 75a and portion 76b of frame 76 with aninsulating strip 86 separating them. The number of bimetal elements andinsulating strips may vary as the amount of current to be handledincreases. The rear piece of bimetal must always have a bent portion 84aas shown tobear against the actuator 80.

Two permanent magnets 88 are placed in recesses in the base 72 above themain stationary contacts 1818, and are held separate from the terminalsby a T-shaped insulator strip 90. The vertical leg of the insulatorstrip 90 extends down between the contacts 1818. These magnets serve toquench any are that may occur during a tripped period due to faultywiring or the like.

Upon calibrating the device by turning screw 78 to either force portion760 outwardly or let it spring inwardly,'the hole 72b would be filledwith a sealant, such as epoxy resin, and the device would be connectedand set in the same manner as the aforedescribed protector. The maincircuit completed in the protector is from terminal 74, through frame76, connector strap 75a, terminal plate 75 stationary contact 18,movable contact assembly 36, the other stationary contact 18 andterminal 20. Normal current flowing through connector strap 74a and thebimetal elements 84 would not be suflicient to effect appreciablewarping of the latter.

Upon an overload current of sufficient duration however, the elementswould become heated in the conventional manner of a bimetal element, andbeingproperly assembled, would warp to the right as viewed in FIG. 9.Portion 84a would then bear against actuator 80, which in turn wouldmove cammed latch surface 54b away from latch plate 36c, therebyreleasing the movable contact assembly to allow it to drop down underthe bias of spring 42, thus breaking the main circuit in the device. Itwill be impossible to reset the device until the bimetal ele ments havecooled sufficiently to return to a position which does not interferewith the cammed surface 54b and latch plate 36c. v

FIGS. 10-12 show a modified latch means for engagement with movablecontact assembly 36. This modification will be described in connectionwith the thermal trip type of device shown in FIGS. 8 and 9, however, itwill be apparent that it could also be used in the magnetic trip type ofdevice shown in FIGS l-6.

As can be seen in FIGS. lO-l2 the modification utilizes a roller type oflatch, therefore substituting rolling friction for sliding friction.Although the sliding friction latch responds to small forces to trip thedevice, the roller latch responds to even smaller forces as directed bythe thermal trip type of device.

A movable contact assembly 92, similar to movable contact assembly 36,is pivotally mounted on a bearing plate 94, which is mounted within thebase by screw 40 similar to plate 38. It can be seen in FIG. 11 that theright-hand end of contactor 92 does not have a downwardly bent bearingportion such as 36a of contactor 36, but is fiat and rests on aninclined surface 94a of bearing plate 94. As a result, the contactor 92is more nearly horizontal in its latched position. Assembly 92 also hasa' hole 92b corresponding to hole 36b of assembly 36. A cage member 920is secured to the underside of assembly 92 in place of the latch plate36c. Cage 920 has a pair of U-shaped leg portions92d which extend alongthe sides of hole 92b. A roller 96 extends transversely between the legs92d and across the opening 92b. The same latching member 54 is used,however, the angle of its latching portion has been reduced from theslightly obtuse angle used with the latch plate to a slightly acuteangle to cradle the roller 96 in the latched position as shown in FIG.11. Roller 96 is restricted from lateral movement by portions of thebase 72, and has rounded thereby rolls to the right along the undersideof member 92, and the latching portion of member 54 rolls off theroller, thereby dropping the member 92 out of engagement with thestationary contacts 18-18. The legs 92d maintain the roller in position,While the device is tripped, so that a resetting action will cause thelatching member to pick up the movable contact member and pull it intoengagement with contacts 18-18.

I claim:

1. A circuit protector comprising a housing, a pair of stationarycontacts mounted in said housing, a contactor pivotally mounted in saidhousing, a spring biasing said contactor away from said stationarycontacts, a reset button, a second spring supporting and biasing saidbutton outwardly of said housing, a pivoted latching lever having itspivots entrapped between said button and said second spring and having aportion extending through an opening in said contactor, said portionhaving a latch surface, a third spring seated in said housing andbiasing said latching lever in a direction to afford engagement of itslatch surface with said contactor.

2. A circuit protector comprising a housing, a pair of stationarycontacts mounted in said housing, a contactor pivotally mounted in saidhousing, a spring biasing said contactor away from said stationarycontacts, a reset button, a second spring supporting and biasing saidbutton outwardly of said housing, a pivoted latching lever having itspivots entrapped between said button and said second spring and having aportion extending through an opening in said contactor, said portionhaving a latch surface, said surface extending beyond said contactorupon inward travel of said button, a third spring seated in said housingand biasing said latching lever in a direction to afford engagement ofits latch surface with said contactor to hold :the latter inengagementwith said stationary contacts against the bias of said firstmentioned spring upon release of said button.

3. The combination according to claim 2 wherein said latching lever isL-shaped, its pivots are at a point common to both legs, and has itslatching surface at the end of one leg, wherein said button andsaidsecond spring afford reciprocable movement of said latching lever,wherein said third spring acts on the other leg of said latching lever,and wherein said third and second springs provide the necessary pivotaland contactor engaging forces on said latching lever necessary to holdand latch said contactor in engagement with said stationary contacts.

4. The combination according to claim 3, wherein said contactor isprovided with a roller supported for limited rolling movement across aportion of the opening and along one side of said contactor, and whereinthe latch surface of said latching lever is formed to engage with saidroller upon release of said button as aforestated.

5. The combination accordingto claim 4, together with a member securedto said one side of said contactor and having alined spaced apartchannel portions which with said one side define a cage for said roller.

6. The combination according to claim 3, together with a manual triplever located within said housing and extending outwardly of the same,and wherein upon inward movement of said manual trip lever it acts uponthe last mentioned leg of said latching lever in a direction op- 8posing the bias and resulting forces of the third mentioned spring.

7. The combination according to claim 6, wherein said manual trip leverhas an offset leg portion overlying said last mentioned leg of saidlatching lever, which, upon inward travel of said manual trip lever,pivots said latching lever in the reverse direction to disengage thesame from said contactor to afford disengagement of the latter from saidstationary contacts under the bias of the first mentioned spring.

8. The combination according to claim 3, together with means within saidhousing responsive to abnormal current flow through the stationarycontacts and contactor closed thereto to pivot said latching lever inthe reverse direction to disengage the same from said contactor toaiford disengagement of the latter from said stationary contacts underthe bias of the first mentioned spring.

9. The combination according to claim 8 wherein said means responsive toabnormal current flow through the stationary contacts and contactorclosed thereto includes a pivoted member which moves to engage and pivotsaid latching lever in the reverse direction.

10. The combination according to claim 3, together with an auxiliaryswitch mounted in said housing and an actuator for said switch, saidactuator being driven by a pivot of said latching lever to provide oneoperating condition of said switch when said latching lever latches saidcontactor in engagement with said stationary contacts and to provideanother operating condition for said switch when said latching lever isdisengaged from said contactor.

11. The combination according to claim 10, wherein said actuatorcomprises a reciprocable member having a longitudinal slot within whichone of the pivots of said latching lever extends and a spring seated atone end of said slot and bearing against the last mentioned pivot ofsaid latching lever to provide a resilient driving connection betweenthe latter and said actuator.

12. The combination according to claim 3, together with a manual triplever located within said housing and extending outwardly of saidhousing, said manual trip lever having an offset leg portion overlyingsaid last mentioned leg portion of said latching lever, which uponinward travel of said normal trip lever pivots said latching lever inthe reverse direction to disengage the same from said contactor toafford disenagement of the latter from said stationery contacts underthe bias of the first mentioned spring, means within said housingresponsive to abnormal current flow through the stationary contacts andcontactor closed thereto, including a pivoted member to engage and pivotsaid latching lever in the reverse direction, an auxiliary switchmounted within said housing and an actuator for said switch, saidactuator comprising a reciprocable member having a longitudinal slotwithin which one of the pivots of said latching lever extends and aspring seated at one end of said slot and bearing against the lastmentioned pivot of said latching lever to provide a resilient drivingconnection between the latter and said switch to provide one operatingcondition of said switch when said latching lever latches said contactorin engagement with said stationary contacts and to provide anotheroperating condition for said switch when said latching lever isdisengaged from said contactor.

No references cited.

BERNARD A, GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,214,537 October 26, 1965 Alvin W. Krieger It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 3, line 10, after "surface" insert 36a which rests on plate 38and allows the contact assembly column 5, line 51, for "differences"read difference Signed and sealed this 20th day of September 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer ioner of Patents

1. A CIRCUIT PROTECTOR COMPRISING A HOUSING, A PAIR OF STATIONARYCONTACTS MOUNTED IN SAID HOUSING, A CONTACTOR PIVOTALLY MOUNTED IN SAIDHOUSING, A SPRING BIASING SAID CONTACTOR AWAY FROM SAID STATIONARYCONTACTS, A RESET BUTTON, A SECOND SPRING SUPPORTING AND BIASING SAIDBUTTON OUTWARDLY OF SAID HOUSING, A PIVOTED FACING LEVER HAVING ITSPIVOTS ENTRAPPED BETWEEN SAID BUTTON AND SAID SECOND SPRING AND HAVING APORTION EXTENDING THROUGH AND OPENING IN SAID CONTACTOR, SAID PORTIONHAVING A LATCH SURFACE, A THIRD SPRING SEATED I/N SAID HOUSING ANDBIASING AND LATCHING LEVER IN A DIRECTION TO AFFORD ENGAGEMENT OF ITSLATCH SURFACE WITH SAID CONTACTOR.